On Wed, May 9, 2012 at 8:24 PM, Joe Wronski <jwronski@stillwatereng.net> wr=
ote:
> Without actually digging into the doc for the 18F part in the example
> (18C452 ?), I can give some answers:
> o Unconditional goto is due to limited program space in the interrupt
> vector area.
> o Retfie is generated by the compiler, probably due to the #pragma
> interrupt directive. =A0Look at View->Disassembly Listing after building.
> o Can't speak to the GIE issue without further digging, but if it is
> disabled by the interrupt mechanism, your cods should re-enable it,
> unless it is implicitly done by the retfie.
>
> There should be no differences in the chip operation whether using C or
> assembler. =A0Always look to the assembler produced by the compiler.
>
> Here is the interrupt exit code produced by C18 including the "missing"
> retfie:
>
> =A0 00F2 =A0 =A052E5 =A0 =A0 MOVF 0xfe5, F, ACCESS
> =A0 00F4 =A0 =A0CFE5 =A0 =A0 MOVFF 0xfe5, 0xfda
> =A0 00F6 =A0 =A0FFDA =A0 =A0 NOP
> =A0 00F8 =A0 =A00011 =A0 =A0 RETFIE 0x1
>
> Joe W
>
>

Missed the #pragma interrupt line here ..

>> void low_isr(void)
>> {
>> =A0 =A0 =A0if ((PIE1bits.TMR2IE =3D=3D 1)&& =A0(PIR1bits.TMR2IF =3D=3D 1=
)) {
>> =A0 =A0 =A0 =A0 =A0PIR1bits.TMR2IF =3D 0;
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 DisplayDigit(segment, display[segment]);
>> =A0 =A0 =A0}
>> =A0 =A0 =A0_asm
>> =A0 =A0 =A0 =A0 =A0retfie 0
>> =A0 =A0 =A0_endasm
>> }
>>
>> #pragma code low_vector =3D 0x18
>> void low_vector (void)
>> {
>> =A0 =A0 =A0_asm goto low_isr _endasm
>> }
>>

missed the #pragma here


This caused the retfie not to appear in the disassembly. Things are sane no=
w.

Thanks,
Manu

--=20
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